1. Field of the Invention
The present invention relates to a switch apparatus for causing an automotive power window to open and close, and more specifically, it relates to a contact structure of a switch apparatus with which a manual down/up operation and an auto down/up operation of a power window can be selectively performed.
2. Description of the Related Art
This type of power window opening and closing switch apparatus is often disposed, for example, on the inner side of the driver side door of an automobile, and is provided with an operation knob that is rockably supported and on which a push operation and a pull operation can be selectively performed, and a detecting means that detects whether or not a predetermined push operation or pull operation is performed on the operation knob. In a typical example of such a detecting means, movable contacts that slide in conjunction with the rocking of the operation knob is brought into and out of contact with fixed contacts on a circuit board.
FIG. 14 is an explanatory view showing a contact structure in a known power window opening and closing switch apparatus (see, for example, Japanese Unexamined Patent Application Publication No. 2008-4322). In the figure, a common fixed contact 31, a manual down fixed contact 32, a manual up fixed contact 33, an auto down fixed contact 34, and an auto up fixed contact 35 are disposed on a circuit board 30, and first to fourth movable contacts 36a to 36d are provided on a slider segment (slider) 36 formed of a conductive metal plate. A driving portion is provided in an operation knob (not shown). When this operation knob is rocked (pushed or pulled), the slider segment 36 driven by the driving portion slides along the circuit board 30. Therefore, the movable contacts 36a to 36d can be brought into and out of contact with the common fixed contact 31 and any one of the other fixed contacts. However, in a neutral state (unoperated state) where the operation knob is not operated, the slider segment 36 is disposed at a neutral position shown in FIG. 14, and therefore the movable contacts 36a to 36d are all out of contact with the fixed contacts 31 to 35. According to the slide position of the slider segment 36, the first movable contact 36a can be brought into and out of contact with the fixed contacts 31 and 32, the second movable contact 36b can be brought into and out of contact with the fixed contacts 31 and 33, the third movable contact 36c can be brought into and out of contact with the fixed contacts 31 and 34, and the fourth movable contact 36d can be brought into and out of contact with the fixed contacts 31 and 35.
That is to say, when the slider segment 36 is at the neutral position shown in FIG. 14, the common fixed contact 31 is not electrically connected with any of the fixed contacts 32 to 35, and therefore a command signal that rotationally drives a power window drive motor is not output. However, with the pushing of the operation knob, the slider segment 36 slides downward in FIG. 14. Therefore, by rotating the operation knob to a halfway pushed position, the switch apparatus can be brought into a state where the first movable contact 36a is in contact with the manual down fixed contact 32, the fourth movable contact 36d is in contact with the common fixed contact 31, and the second movable contact 36b and the third movable contact 36c are out of contact with the fixed contacts 31 and 34, respectively. Thus, the manual down fixed contact 32 and the common fixed contact 31 are electrically connected with each other through the slider segment 36, and therefore a command signal is output that causes the power window to perform opening operation, and the motor is driven in the forward direction. When the operation force is removed in this state, the operation knob is automatically returned to the neutral position shown in FIG. 14 by the elastic force of a return spring (not shown), and therefore the opening operation of the power window stops. By rotating the operation knob to a fully pushed position, the switch apparatus can be brought into a state where the third movable contact 36c is in contact with the auto down fixed contact 34 and the second movable contact 36b is in contact with the common fixed contact 31. Thus, the auto down fixed contact 34 and the common fixed contact 31 are electrically connected with each other through the slider segment 36, and therefore a command signal is output that causes the power window to open fully, and the motor is driven in the reverse direction until the power window opens fully.
On the other hand, with the pulling of the operation knob, the slider segment 36 slides upward in FIG. 14. Therefore, by rotating the operation knob to a halfway pulled position, the switch apparatus can be brought into a state where the second movable contact 36b is in contact with the manual up fixed contact 33, the third movable contact 36c is in contact with the common fixed contact 31, and the first movable contact 36a and the fourth movable contact 36d are out of contact with the fixed contacts 31 and 35, respectively. Thus, the manual up fixed contact 33 and the common fixed contact 31 are electrically connected with each other through the slider segment 36, and therefore a command signal is output that causes the power window to perform closing operation, and the motor is driven in the reverse direction. When the operation force is removed in this state, the operation knob is automatically returned to the neutral position shown in FIG. 14, and therefore the closing operation of the power window stops. By rotating the operation knob to a fully pulled position, the switch apparatus can be brought into a state where the first movable contact 36a is in contact with the common fixed contact 31 and the fourth movable contact 36d is in contact with the auto up fixed contact 35. Thus, the auto up fixed contact 35 and the common fixed contact 31 are electrically connected with each other through the slider segment 36, and therefore a command signal is output that causes the power window to close fully, and the motor is driven in the reverse direction until the power window closes fully.
In the known power window opening and closing switch apparatus having such a contact structure, the common fixed contact 31 is substantially equidistant from the four fixed contacts 32 to 35. Therefore, four types of signals (a manual down command signal, an auto down command signal, a manual up command signal, and an auto up command signal) according to the pushing and pulling of the operation knob can be reliably derived. In addition, because all of the fixed contacts 31 to 35 can be disposed in an elongate region on the circuit board 30, the switch apparatus 1 has a good space factor and can be easily reduced in size.
However, in the case of a power window opening and closing switch apparatus in which five fixed contacts 31 to 35 are distributed on a circuit board 30 as in the above-described known switch apparatus, wiring patterns for the five fixed contacts 31 to 35 need to be formed on the circuit board 30. For this reason, the wiring layout on the circuit board 30 tends to be complex and dense. This limits the degree of freedom of circuit design and increases the manufacturing cost.